The last week has been a turbulent one for U.S. Steel (NYSE: X  ) , AK Steel (NYSE: AKS  ) , and Steel Dynamics (NASDAQ: STLD  ) . These three companies, and indeed thewider U.S. steel industry in general, have been buffeted by a barrage of newsregarding import tariffs.

The good news came in the form of the Commerce Department's decisionto place hefty import tariffs on some steel companies importing steel fromKorea. This move followed claims that some Korean companies had been dumpingcheap steel tubes into U.S. steel markets, denting sales of domestic producers.

Dumping steel

Over the past decade, steel producers across Asia, especially inChina, have been looking to boost profits by selling their products in U.S.markets. This influx of low-cost steel hit the industry hard, and companiesstarted to lobby hard for policymakers to step in.

Finally, during 2010, policy makers levied import duties on Chinesesteel; this was a victory for the American steel industry. However, the importsdid not stop as other Asian producers stepped into the void.